1. Technical Field
The present invention relates to a method for use in an analytical furnace.
2. Description of Related Art
Analyzers can be used to measure or calculate a product's weight, moisture, volatiles, fixed carbon, ash, etc. of a sample. Often an analyzer utilizes a furnace or other heat source to heat a sample. One type of analyzer is a thermogravimetric analyzer which periodically weighs the sample. The analyzer utilizes ASTM standards to analyze the sample and provide the desired reading. The sample is first initially weighed. Thereafter it is subjected to a controlled temperature profile where it is periodically weighed to determine weight loss. The moisture content can be calculated based on the measured weight loss.
The temperature of the sample within the analyzer is measured and controlled using a temperature sensor such as a thermocouple. Often thermocouples and other temperature measuring devices drift and become inaccurate over time. As the thermocouples become inaccurate, the control scheme which controls the temperature of the sample often subjects the sample to non-uniform temperature ramp-up which affects the amount and rate of moisture loss from the sample. As such, the temperature profile is not accurately known or controlled, which can result in increased error and variability. Accordingly, it is desirable to have a method which accounts for and overcomes this inaccuracy.